Rheostat



E. C. FASOLDT.

RHEOSTAT. APPLICATION FILED APR. 7, 1922.

Patentemifiegm M. and 1 .7 m &

WITNESSES Patented Sept. 19, 1922.

PATEN OFFICE;

was: ormnnnsrn'sotnr, OFAVLBIANY, New YORK, AssIcNoR- or 'rwo-rirrans'ro LOUIS R. use, or ALBANY, New Y RK,

nnnosrar.

, Application filed April 7, 1922. Serial No. 550,370.

Toa llwhomit'may concern:

Be: 't known that I, EnNEsr Cd FAsorn'f,

a citizen of the United States, and a :resident of Albany, in the county of Albany and \State of New York, have invented a new and Improved Rheostat, of which the following is a full, clear, and exact description. r This invention" relates to improvements in .10 i to provide a rheostat capable of micrometer "adjustment.

A; furtherobject is to providefa rheostat ucapable of such delicate adjustment that the same may be used as a potentiometer, and a rheostat which provides'for a micro-ampere flow of current, such as islusedin a vacuum tube for the reception of a telegraph, or with other apparatus, as in wireless or radio receiving outfits. i i

A stifi' further object is to provide a device of this character, which will be simple use, and which will lenditself to economical manufacture. With these and other objects in view, the invention consists in certain novel features of construction, and combinations and arrangements of parts as will bemore fully' hereinafter described and pointed out in the claims.

In the accompanying drawings Figure l is 'a top plan view of my inrproved rheostat; and

therethrough on the staggered line 2-2 of Figure 1.

Referring in detail to the drawings, I have used the reference numeral 1 to designate the body portion of my improved rheostat, which is formed of some insulating material and provided with an integral flanged base 2. Binding posts 3 and 4 are mounted at diametrically opposed points upon the base for the attachment of electric wires 5 and 6 respectively. The body 1 includes a hollow center accommodating'an internally screw threaded brass sleeve 7, in which a hollow screw 8is movable.

The body 1 is externally threaded, as indicated at 9, the external threads of the base and the internal threads of the sleeve being similarly pitched. Resistance wire 10 is wrapped in the external threads of the rheostats, an object of the invention being sistance coil.

Figure 2 is a transverse sectional view body l and suitably connected to the binding post 4', as indicated at 11; The screw 8 terminates-in an upwardly presented shank 12, upon which an insulated cap or handle 13, issecured by a nut 14 screwed onto the upper end of the post and located in a recess 15in the top of the cap.

The reduced upper end or shank of the screw, 8,;provides a shoulder '16 on the screw which supportsa circular metallic plate 17 slipped over the shank and held against the shoulder by the cap 13. The plate 17 carries .at spaced intervals depending spring fingers l8 contacting with the wireof the re- I preferably utilize three or four of these fingers. Contact between the binding post 3 and the screw8 is established by an arm 19 connected. to the binding post and extending below the base 2 and sleeve 7, which serves to support a coiled expansion spring 20 extending upwardly into tween the screw and the arm.

When the device is in operation, current passes from the wire 5 through the post 3, arm 19, spring 20, sleeve 7, plate 17 and fingers 18, to the resistance coil, from the hollow screw 8 and making contact be- 7 and practical in construction, efficient-in whence it flows to the other binding post i 4 and wire 6. Any desired amount of resistance may be thrown out or in by simply turning the cap or handle 13 to raise or lower the screw 8, and consequently, the fingers 18 which contact with the resistance wire. By virtue of this screw threaded adjustment it will be seen that an exceedingly delicate instrument is provided and that thrown in or out.

I have illustrated one of the preferred embodiments of my invention, but numerous slight changes and alterations might be made in the general form'and arrangement of the parts described. without departing from the invention, and hence I do not wish to limit myself to the precise details set forth, but shall consider myself at liberty to make such slight changes and alterany desired amount of resistance may be ations as fairly fall within the spirit and scope of the appended claims.

I claim: 7 1. In a rheostat, a body of insulating material, a resistance coil spirally wound around the body, an internally threaded sleeve in the body, a screw movable in the sleeve, 21 plate fi J1 Sprmgr fingers uvu a'ni 'ivjzih tacting with the coil to 5121i posts a yes Sham-u 0'11 spirally current How and a handle 01: 1 E naiy my} "1), c0. 5 terml IQSQill 4'11 Hm plate m SSE? an interim screw 35 the screw for fiurning the sin 1-2- 2. In :1 rhe 1, a body (If nsuiatmg *wardl em'cz'ldingg term], a iCfwlnbIlllOj c011 spu'zhy W01 11d. -,z1-301lefl around the bod an zz'itemalj y tlfieuuai bsshave and haviw' U 510M (3211'? ed by 4 M mi by inn 111g; :1 1 01mm? rough winch the 41 1 own mmlmtilcy 11mg (is and ywovnled 11 he scrvw to "tag;

of the screw cs spring: fingers en :1 handla n1 shank 01'? r ing the handle a m the SCE'GW.

in a iaoftat F 29 6331 21 '1 1m n ;1

id 00?, mm

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